A ripple ran through the travel and lodging industry Tuesday following deadly attacks in Belgium that killed dozens of people at the Brussels airport and in the city’s subway.

American Airlines, Delta and United Airlines cancelled or diverted all flights to and from Brussels, where the airport was closed.

Security was tightened across Europe, just four months after coordinated attacks in Paris killed 130 people. Air travel and hotel bookings in Paris dipped in the aftermath.

But apprehension about travel, at least Tuesday, was global.

“While the attacks took place in Brussels, it is likely to have an impact on European travel demand in general,” said Raymond James analyst Savanthi Syth, in a note to clients. “The attacks come during peak Easter travel and ahead of peak summer travel.”